Silicon carbide semiconductor devices having structures that include pn junctions and perform bipolar operations have conventionally had problems that in a case where currents flow in a forward direction of the pn junctions, recombination currents of the pn junctions expand a lamination defect due to a crystal defect, resulting in an increase in a resistance of the forward characteristics. The crystal defect causing the lamination defect is formed in steps of manufacturing semiconductor substrates and epitaxial layers on the semiconductor substrates.
For example, Japanese Patent Application Laid-Open No. 2010-135573 proposes a technique for observing location coordinates of a crystal defect in a substrate by an optical microscope or the like in advance to prevent the crystal defect included in an epitaxial layer of the semiconductor device and for forming an element region in a position that avoids the location coordinates of the crystal defect.